Auxiliary power supplies can be used to provide electric power to controllers, switch gate driving circuits and/or sensors of power electronic converters. In high voltage applications, these devices can be used to drive a gate drive circuit. Examples of high voltage systems that utilize auxiliary power supplies include high voltage direct current (HVDC) transmission systems, flexible alternating current transmission systems (FACTS), static synchronous compensator (STATCOM) systems, motor drive systems, and the like. For these high voltage systems, multi-level converters with cascaded structures, such as a modular multi-level converter (MMC) system or a cascaded multi-level inverter system, have become desirable.
MMC systems, or also known as Chain-Link Converter (CLC) systems, include a plurality of converter cells, or converter sub-modules, that can be serially connected in converter branches, or phase legs, that in turn can be arranged in a wye/star, delta, and/or indirect converter topology. Each converter sub-module can include a half-bridge or a full-bridge circuit, and a capacitor. Each of the half-bridge or full-bridge circuits can include switching devices such as insulated-gate bipolar transistors (IGBTs), gate-turn-off thyristors (IGCTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs), or the like. Each converter sub-module of the MMC system can be coupled to a separate gate drive system. Each gate drive system can include a gate driver (e.g., an amplifier) and a corresponding auxiliary power supply. The gate driver can be configured to drive the switching device based on an output voltage generated by the corresponding auxiliary power supply.